Conventionally, ball screws, linear guides, linearly driven type bearings, ball splines and the like are known as rolling devices. Each of these rolling devices such as ball screw is provided with: an inner member having an outer surface in which a rolling member rolling surface is formed; an outer member disposed outside the inner member and having a loaded rolling surface opposing to the rolling member rolling surface; and a number of rolling members disposed to be capable of rolling in a loaded rolling passage formed by the rolling member rolling surface and the load rolling surface, in which rotational motion and linear motion of the outer member relative to the inner member are permissible.
With such rolling device, a number of rolling members disposed between the inner member and the outer member roll repeatedly, so that contacting stress is repeatedly applied to constructional members of the rolling device. Because of this reason, metal materials or resin materials excellent in anti-fatigue life and friction-proof property are used for materials constituting the inner and outer members of the rolling device.
However, the conventional technology provides a case such that when a number of rolling members circulate along the rolling passage, noises are caused by mutual contact of the rolling members or contact of the rolling member rolling in the outer member against a wall surface of the rolling passage. In a conventional technology, in order to reduce such noises, a retainer is interposed between the rolling members to prevent the rolling members from contacting, or a sound isolation member is disposed so as to cover a member constituting a scoop portion and a rolling direction changing portion, at which the noises are liable to be generated. Furthermore, a seal member is disposed to an end portion of the outer member so as to remove foreign material on the rolling passage or prevent lubricating agent applied on the rolling member from leaking outside of the outer member.
As prior art publications disclosing noise reducing technology for the rolling devices mentioned above, the following Patent Publication 1 will be provided.    Patent Publication 1: Japanese Patent Application Laid-open Publication No. 2005-308081